service/internal.RunOutput: fix both #110 and #156 properly

host/service/internal/run_unix.go

@@ -1,7 +1,7 @@
 package internal
 
 import (
-	"bufio"
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -17,40 +17,43 @@ func Run(command string, arguments ...string) error {
 	return err
 }
 
-func RunOutput(command string, args ...string) (string, error) {
-	var stdout string
+func RunOutput(command string, args ...string) (out string, err error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-	defer cancel()
+	var stdout, stderr bytes.Buffer
+	defer func() {
+		cancel()
+		if err != nil {
+			err = fmt.Errorf("%s %s: %w: %s", command, strings.Join(args, " "), err, stderr.String())
+		}
+	}()
 	cmd := exec.CommandContext(ctx, command, args...)
 	// Obtain a pipe connected to our cmd stdout so we can read from it later.
 	// cmd.Output() would block here because the underlying pipes are not closed
 	// and it will try to read from them indefinitely
-	stdoutPipe, err := cmd.StdoutPipe()
-	if err != nil {
-		cancel()
-		return "", fmt.Errorf("%s %s: %w", command, strings.Join(args, " "), err)
+	var stdoutPipe, stderrPipe io.ReadCloser
+	if stdoutPipe, err = cmd.StdoutPipe(); err != nil {
+		err = fmt.Errorf("cannot connect stdout: %w", err)
+		return
+	}
+	if stderrPipe, err = cmd.StderrPipe(); err != nil {
+		err = fmt.Errorf("cannot connect stderr: %w", err)
+		return
 	}
 	if err = cmd.Start(); err != nil {
-		cancel()
-		return "", fmt.Errorf("%s %s: %w", command, strings.Join(args, " "), err)
+		return
 	}
-	go func(stdout string, stdoutPipe io.ReadCloser) {
-		buf := bufio.NewReader(stdoutPipe)
-		for {
-			line, _ := buf.ReadString('\n')
-			if len(line) > 0 {
-				stdout = stdout + line + "\n"
-			}
-		}
-	}(stdout, stdoutPipe)
-	err = cmd.Wait()
-	if err != nil {
-		cancel()
-		return "", fmt.Errorf("%s %s: %w", command, strings.Join(args, " "), err)
+	go copy(&stdout, stdoutPipe)
+	go copy(&stderr, stderrPipe)
+	if err = cmd.Wait(); err != nil {
+		return
 	}
-	return stdout, nil
+	out = strings.TrimSpace(stdout.String())
+	return
 }
 
+func copy(w io.Writer, r io.ReadCloser) {
+	_, _ = io.Copy(w, r)
+}
 func ExitCode(err error) int {
 	if err == nil {
 		return 0

host/service/systemd/service.go

@@ -4,7 +4,6 @@ package systemd
 
 import (
 	"errors"
-	"fmt"
 	"os"
 	"os/exec"
 	"strings"
@@ -53,7 +52,6 @@ func (s Service) Uninstall() error {
 
 func (s Service) Status() (service.Status, error) {
 	out, err := internal.RunOutput("systemctl", "is-active", s.Name)
-	fmt.Println(out, err)
 	if internal.ExitCode(err) == 0 && err != nil {
 		return service.StatusUnknown, err
 	}